Techniques for beam pattern adjustments in a LIDAR system

ABSTRACT

A system and method include receiving a first beam pattern from an optical source that comprises a plurality of optical beams transmitted towards a target causing different spaces to form between each optical beam. The system and method include measuring a vertical angle between at least two of the optical beams along a first axis and calculating a second beam pattern based on the vertical angle and a pivot point that causes the optical beams to be transmitted towards the target with substantially uniform spacing. The system and method include adjusting, at the pivot point, one or more components to form the second beam pattern to adjust the plurality of different spaces to the substantially uniform spacing for transmission towards the target. The system and method include receiving return optical beams from the target to produce a plurality of points to form the point cloud.

TECHNICAL FIELD

The present disclosure relates generally to optical beam patterns, andmore particularly to systems and methods for adjusting a beam pattern ina frequency-modulated continuous wave (FMCW) light detection and ranging(LIDAR) system.

BACKGROUND

Frequency-modulated continuous wave (FMCW) LIDAR systems use tunablelasers for frequency-chirped illumination of targets and coherentreceivers for detection of backscattered or reflected light from thetargets, which are combined with a local copy of the transmitted signal(LO signal). Conventional LIDAR systems require high frame rates and anincreased number of scanning points typically achieved by using multiplenumbers of optical beams. The optical beams may be placed in aone-dimensional or two-dimensional array separated by a pitch. Anoptical source may collimate the optical beams using a single outputlens, which provides a vertical angle between the collimated opticalbeams to form a beam pattern. A challenge found with using suchconfigurations is the inflexibility to individually adjust each opticalbeam's position relative to the other optical beams to form a beampattern. In addition, based on assembly processes, material properties,part tolerances, environmental conditions, and etcetera, the beampattern produced by the optical source may not provide acceptable beamspacings between the optical beams along an axis relative to the LIDARsystem which, in turn, can cause object detection issues.

BRIEF SUMMARY

A system of one or more computers can be configured to performparticular operations or actions by virtue of having software, firmware,hardware, or a combination of them installed on the system that inoperation causes or cause the system to perform the actions. One or morecomputer programs can be configured to perform particular operations oractions by virtue of including instructions that, when executed by dataprocessing apparatus, cause the apparatus to perform the actions. Oneaspect disclosed herein is directed to a method of adjusting a beampattern to form a point cloud in a frequency-modulated continuous wave(FMCW) light detection and ranging (LIDAR) system. As discussed herein,an FMCW LIDAR system may also be referred to as a LIDAR system.

In some embodiments, the method includes receiving a beam pattern froman optical source. In some embodiments, the beam pattern includesoptical beams transmitted towards a target to cause different spaces toform between each optical beam of the optical beams. In someembodiments, the method also includes measuring a vertical angle betweenthe optical beams along an axis relative to the FMCW LIDAR system. Insome embodiments, the method also includes calculating, using aprocessor, an adjusted beam pattern based on the vertical angle and apivot point within the FMCW LIDAR system that causes the optical beamsto be transmitted towards the target with substantially uniform spacingbetween each optical beam of the optical beams. In some embodiments, themethod also includes adjusting, at the pivot point, components from aposition that forms the beam pattern to an adjusted position that formsthe adjusted beam pattern in the FMCW LIDAR system, which adjusts thedifferent spaces to the substantially uniform spacing for transmissiontowards the target. In some embodiments, the method also includesreceiving return optical beams from the target, based on the adjustedbeam pattern, to produce points to form the point cloud. Otherembodiments of this aspect include corresponding computer systems,apparatus, and computer programs recorded on one or more computerstorage devices, each configured to perform the actions of the methods.

In some embodiments, the optical beams form a vertical anglecorresponding to the beam pattern and form an adjusted vertical anglecorresponding to the adjusted beam pattern. The vertical angle and theadjusted vertical angle are both vertical components of angularseparation in a scan frame between the two optical beams.

In some embodiments, a portion of the adjusting of the componentsrotates the optical source about a different axis relative to the axis.In some embodiments, the adjusting may include rotating a scanner abouta different axis not parallel to the axis. In some embodiments, themethod may include receiving the beam pattern from the scanner at adifferent scanner, and the adjusting further may include rotating thedifferent scanner until the adjusted beam pattern is formed. In someembodiments, the method may include analyzing the point cloud anddynamically re-adjusting, responsive to analyzing the point cloud, thecomponents to re-create the adjusted beam pattern. In some embodiments,the method may include detecting an object in the point cloud,determining another beam pattern based on the object, and adjusting, atthe pivot point, the components to a different position that forms theother beam pattern in the FMCW LIDAR system. Implementations of thedescribed techniques may include hardware, a method or process, orcomputer software on a computer-accessible medium.

In another aspect, the present disclosure is directed to FMCW LIDARsystem that includes an optical source to generate a beam pattern mayinclude optical beams transmitted towards a target to cause differentspaces to form between each optical beam of the optical beams. In someembodiments, the FMCW LIDAR systems includes a memory to storeinstructions and a processor coupled to the memory that, when executingthe set of instructions, is configured to measure a vertical anglebetween the optical beams along an axis relative to the FMCW LIDARsystem. In some embodiments, the processor is configured to calculate anadjusted beam pattern based on the vertical angle and a pivot pointwithin the FMCW LIDAR system that causes the optical beams to betransmitted towards the target with substantially uniform spacingbetween each optical beam of the optical beams. In some embodiments, theprocessor is configured to adjust, at the pivot point, the componentsfrom a position that forms the beam pattern to an adjusted position thatforms the adjusted beam pattern in the FMCW LIDAR system to adjust thedifferent spaces to the substantially uniform spacing for transmissiontowards the target. In some embodiments, the processor is configured toreceive return optical beams from the target, based on the adjusted beampattern, to produce points to form a point cloud.

In another aspect, the system includes an FMCW LIDAR system with anoptical assembly that includes an optical source and scanners. In someembodiments, the optical assembly to generate a beam pattern thatincludes optical beams transmitted towards a target to cause differentspaces to form between each optical beam of the optical beams. In someembodiments, the optical assembly includes a beam pattern adjustmentassembly. In some embodiments, the beam pattern adjustment assembly toadjust, at a pivot point, components from a position that forms the beampattern to an adjusted position that forms an adjusted beam pattern. Insome embodiments, the FMCW LIDAR system also includes a LIDAR controlsystem coupled to the optical assembly. In some embodiments, the LIDARcontrol system includes one or more processors to measure a verticalangle between the optical beams along an axis relative to the FMCW LIDARsystem. In some embodiments, the LIDAR control system to calculate theadjusted beam pattern based on the vertical angle and the pivot pointwithin the FMCW LIDAR system that causes the optical beams to betransmitted towards the target with substantially uniform spacingbetween each optical beam of the optical beams. In some embodiments, theLIDAR control system to instruct the beam pattern adjustment assembly toperform the adjusting. In some embodiments, the LIDAR control system toreceive return optical beams from the target, based on the adjusted beampattern, to produce points to form a point cloud. Other embodiments ofthis aspect include corresponding computer systems, apparatus, andcomputer programs recorded on one or more computer storage devices, eachconfigured to perform the actions of the methods.

These and other features, aspects, and advantages of the presentdisclosure will be apparent from a reading of the following detaileddescription together with the accompanying figures, which are brieflydescribed below. The present disclosure includes any combination of two,three, four or more features or elements set forth in this disclosure,regardless of whether such features or elements are expressly combinedor otherwise recited in a specific example implementation describedherein. This disclosure is intended to be read holistically such thatany separable features or elements of the disclosure, in any of itsaspects and example implementations, should be viewed as combinableunless the context of the disclosure clearly dictates otherwise.

It will therefore be appreciated that this Summary is provided merelyfor purposes of summarizing some example implementations so as toprovide a basic understanding of some aspects of the disclosure.Accordingly, it will be appreciated that the above described exampleimplementations are merely examples and should not be construed tonarrow the scope or spirit of the disclosure in any way. Other exampleimplementations, aspects, and advantages will become apparent from thefollowing detailed description taken in conjunction with theaccompanying figures which illustrate, by way of example, the principlesof some described example implementations.

BRIEF DESCRIPTION OF THE FIGURE(S)

Embodiments and implementations of the present disclosure will beunderstood more fully from the detailed description given below and fromthe accompanying drawings of various aspects and implementations of thedisclosure, which, however, should not be taken to limit the disclosureto the specific embodiments or implementations, but are for explanationand understanding only.

FIG. 1 is a block diagram illustrating an example of a LIDAR system,according to some embodiments.

FIG. 2 is a time-frequency diagram illustrating an example of an FMCWscanning signal that can be used by a LIDAR system to scan a targetenvironment, according to some embodiments.

FIGS. 3A-3B are block diagrams depicting examples of adjusting a beampattern originating from an optical source that transmits two opticalbeams.

FIGS. 4A-4B are block diagrams depicting examples of adjusting a beampattern originating from an optical source that transmits four opticalbeams.

FIGS. 5A-5D depict various embodiments of transforming a beam pattern toan adjusted beam pattern.

FIG. 6 is a block diagram depicting an example of using a beammeasurement system to calibrate a LIDAR system.

FIG. 7 is a block diagram depicting an example of dynamically adjustingthe beam patterns in real-time based on point cloud analysis.

FIG. 8 is a flow diagram of an example method for adjusting a beampattern in an FMCW LIDAR system.

DETAILED DESCRIPTION

According to some embodiments, the described LIDAR system describedherein may be implemented in any sensing market, such as, but notlimited to, transportation, manufacturing, metrology, medical, virtualreality, augmented reality, and security systems. According to someembodiments, the described LIDAR system is implemented as part of afront-end of frequency modulated continuous-wave (FMCW) device thatassists with spatial awareness for automated driver assist systems, orself-driving vehicles.

As will be described in greater detail herein, embodiments of thepresent disclosure include an optical source that includes thefunctionality to produce a beam pattern with vertical angles betweencollimated optical beams. Embodiments of the present disclosure includeapproaches to both statically and dynamically perform beam patternadjustments in an FMCW LIDAR system to meet stringent beam spacingspecifications.

FIG. 1 is a block diagram illustrating an example of a LIDAR system,according to some embodiments. The LIDAR system 100 includes one or moreof each of a number of components, but may include fewer or additionalcomponents than shown in FIG. 1 . One or more of the components depictedin FIG. 1 can be implemented on a photonics chip, according to someembodiments. The optical circuits 101 may include a combination ofactive optical components and passive optical components. Active opticalcomponents may generate, amplify, and/or detect optical signals and thelike. In some examples, the active optical component includes opticalbeams at different wavelengths, and includes one or more opticalamplifiers, one or more optical detectors, or the like. In someembodiments, one or more LIDAR systems 100 may be mounted onto any area(e.g., front, back, side, top, bottom, and/or underneath) of a vehicleto facilitate the detection of an object in any free-space relative tothe vehicle. In some embodiments, the vehicle may include a steeringsystem and a braking system, each of which may work in combination withone or more LIDAR systems 100 according to any information (e.g., one ormore rigid transformations, distance/ranging information, Dopplerinformation, etc.) acquired and/or available to the LIDAR system 100. Insome embodiments, the vehicle may include a vehicle controller thatincludes the one or more components and/or processors of the LIDARsystem 100.

Free space optics 115 may include one or more optical waveguides tocarry optical signals, and route and manipulate optical signals toappropriate input/output ports of the active optical circuit. Inembodiments, the one or more optical waveguides may include one or moregraded index waveguides, as will be described in additional detail belowat FIGS. 3-6 . The free space optics 115 may also include one or moreoptical components such as taps, wavelength division multiplexers (WDM),splitters/combiners, polarization beam splitters (PBS), collimators,couplers or the like. In some examples, the free space optics 115 mayinclude components to transform the polarization state and directreceived polarized light to optical detectors using a PBS, for example.The free space optics 115 may further include a diffractive element todeflect optical beams having different frequencies at different anglesalong an axis (e.g., a fast-axis).

In some examples, the LIDAR system 100 includes an optical scanner 102that includes one or more scanning mirrors that are rotatable along anaxis (e.g., a slow-axis) that is orthogonal or substantially orthogonalto the fast-axis of the diffractive element to steer optical signals toscan an environment according to a scanning pattern. For instance, thescanning mirrors may be rotatable by one or more galvanometers. Objectsin the target environment may scatter an incident light into a returnoptical beam or a target return signal. The optical scanner 102 alsocollects the return optical beam or the target return signal, which maybe returned to the passive optical circuit component of the opticalcircuits 101. For example, the return optical beam may be directed to anoptical detector by a polarization beam splitter. In addition to themirrors and galvanometers, the optical scanner 102 may includecomponents such as a quarter-wave plate, lens, anti-reflective coatedwindow or the like.

To control and support the optical circuits 101 and optical scanner 102,the LIDAR system 100 includes LIDAR control systems 110. The LIDARcontrol systems 110 may include a processor or processing device for theLIDAR system 100. In some examples, the processor or processing devicemay be one or more general-purpose processing devices such as amicroprocessor, central processing unit, or the like. More particularly,the processing device may be complex instruction set computing (CISC)microprocessor, reduced instruction set computer (RISC) microprocessor,very long instruction word (VLIW) microprocessor, or processorimplementing other instruction sets, or processors implementing acombination of instruction sets. The processor or processing device mayalso be one or more special-purpose processing devices such as anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), a digital signal processor (DSP), network processor,or the like.

In some examples, the LIDAR control system 110 may include a processoror processing device that may be implemented with a DSP, such as signalprocessing unit 112. The LIDAR control systems 110 are configured tooutput digital control signals to control optical drivers 103. In someexamples, the digital control signals may be converted to analog signalsthrough signal conversion unit 106. For example, the signal conversionunit 106 may include a digital-to-analog converter. The optical drivers103 may then provide drive signals to active optical components ofoptical circuits 101 to drive optical sources such as lasers andamplifiers. In some examples, several optical drivers 103 and signalconversion units 106 may be provided to drive multiple optical sources.

In some embodiments, LIDAR control systems 110 include beam patternadjustment module 113 (e.g., software code). In some embodiments, signalprocessing unit 112 executes beam pattern adjustment module 113 andinterfaces with beam pattern adjustment controller 116 to adjust variousoptical components. In some embodiments, adjustment components 117, 118,and 119 are, for example, actuators that introduce rotational elementsinto the beam pattern by rotating optical sources and/or scanners inoptical circuits 101, free space optics 115, and/or optical scanner 102,respectively, to achieve a desired beam pattern. In some embodiments,signal processing unit 112 communicates directly with adjustmentcomponents 117, 118, and 119 to adjust optical circuits 101, free spaceoptics 115, and/or optical scanner 102.

In some embodiments, signal processing unit 112, when executing beampattern adjustment module 113, can use apriori data, stored in residentcomputer memory, that includes desired beam spacing specifications toform the control signals that instruct scanners and/or optical sourcesto rotate about a predefined pivot point within the LIDAR system 100.Predefined pivot points may include, but are not limited to, points thata component can rotate about in order to rotate the beams with respectto a scanning direction of LIDAR system 100.

The LIDAR control systems 110 are also configured to output digitalcontrol signals for the optical scanner 102. A motion control system 105may control the galvanometers of the optical scanner 102 based oncontrol signals received from the LIDAR control systems 110. Forexample, a digital-to-analog converter may convert coordinate routinginformation from the LIDAR control systems 110 to signals interpretableby the galvanometers in the optical scanner 102. In some examples, amotion control system 105 may also return information to the LIDARcontrol systems 110 about the position or operation of components of theoptical scanner 102. For example, an analog-to-digital converter may inturn convert information about the galvanometers' position to a signalinterpretable by the LIDAR control systems 110.

The LIDAR control systems 110 are further configured to analyze incomingdigital signals. In this regard, the LIDAR system 100 includes opticalreceivers 104 to measure one or more beams received by optical circuits101. For example, a reference beam receiver may measure the amplitude ofa reference beam from the active optical component, and ananalog-to-digital converter converts signals from the reference receiverto signals interpretable by the LIDAR control systems 110. Targetreceivers measure the optical signal that carries information about therange and velocity of a target in the form of a beat frequency,modulated optical signal. The reflected beam may be mixed with a secondsignal from a local oscillator. The optical receivers 104 may include ahigh-speed analog-to-digital converter to convert signals from thetarget receiver to signals interpretable by the LIDAR control systems110. In some examples, the signals from the optical receivers 104 may besubject to signal conditioning by signal conditioning unit 107 prior toreceipt by the LIDAR control systems 110. For example, the signals fromthe optical receivers 104 may be provided to an operational amplifierfor amplification of the received signals and the amplified signals maybe provided to the LIDAR control systems 110.

In some applications, the LIDAR system 100 may additionally include oneor more imaging devices 108 configured to capture images of theenvironment, a global positioning system 109 configured to provide ageographic location of the system, or other sensor inputs. The LIDARsystem 100 may also include an image processing system 114. The imageprocessing system 114 can be configured to receive the images andgeographic location, and send the images and location or informationrelated thereto to the LIDAR control systems 110 or other systemsconnected to the LIDAR system 100.

In operation according to some examples, the LIDAR system 100 isconfigured to use nondegenerate optical sources to simultaneouslymeasure range and velocity across two dimensions. This capability allowsfor real-time, long range measurements of range, velocity, azimuth, andelevation of the surrounding environment.

In some examples, the scanning process begins with the optical drivers103 and LIDAR control systems 110. The LIDAR control systems 110instruct, e.g., via signal processing unit 112, the optical drivers 103to independently modulate one or more optical beams, and these modulatedsignals propagate through the optical circuits 101 to the free spaceoptics 115. The free space optics 115 directs the light at the opticalscanner 102 that scans a target environment over a preprogrammed patterndefined by the motion control system 105. The optical circuits 101 mayalso include a polarization wave plate (PWP) to transform thepolarization of the light as it leaves the optical circuits 101. In someexamples, the polarization wave plate may be a quarter-wave plate or ahalf-wave plate. A portion of the polarized light may also be reflectedback to the optical circuits 101. For example, lensing or collimatingsystems used in LIDAR system 100 may have natural reflective propertiesor a reflective coating to reflect a portion of the light back to theoptical circuits 101.

Optical signals reflected back from an environment pass through theoptical circuits 101 to the optical receivers 104. Because thepolarization of the light has been transformed, it may be reflected by apolarization beam splitter along with the portion of polarized lightthat was reflected back to the optical circuits 101. In such scenarios,rather than returning to the same fiber or waveguide serving as anoptical source, the reflected signals can be reflected to separateoptical receivers 104. These signals interfere with one another andgenerate a combined signal. The combined signal can then be reflected tothe optical receivers 104. Also, each beam signal that returns from thetarget environment may produce a time-shifted waveform. The temporalphase difference between the two waveforms generates a beat frequencymeasured on the optical receivers 104 (e.g., photodetectors).

The analog signals from the optical receivers 104 are converted todigital signals by the signal conditioning unit 107. These digitalsignals are then sent to the LIDAR control systems 110. A signalprocessing unit 112 may then receive the digital signals to furtherprocess and interpret them. In some embodiments, the signal processingunit 112 also receives position data from the motion control system 105and galvanometers (not shown) as well as image data from the imageprocessing system 114. The signal processing unit 112 can then generate3D point cloud data (sometimes referred to as, “a LIDAR point cloud”)that includes information about range and/or velocity points in thetarget environment as the optical scanner 102 scans additional points.In some embodiments, a LIDAR point cloud may correspond to any othertype of ranging sensor that is capable of Doppler measurements, such asRadio Detection and Ranging (RADAR). The signal processing unit 112 canalso overlay 3D point cloud data with image data to determine velocityand/or distance of objects in the surrounding area. The signalprocessing unit 112 also processes the satellite-based navigationlocation data to provide data related to a specific global location.

FIG. 2 is a time-frequency diagram illustrating an example of an FMCWscanning signal that can be used by a LIDAR system to scan a targetenvironment, according to some embodiments. In one example, the scanningwaveform 201, labeled as fFM(t), is a sawtooth waveform (sawtooth“chirp”) with a chirp bandwidth ΔfC and a chirp period TC. The slope ofthe sawtooth is given as k=(ΔfC/TC). FIG. 2 also depicts target returnsignal 202 according to some embodiments. Target return signal 202,labeled as fFM(t−Δt), is a time-delayed version of the scanning signal201, where Δt is the round trip time to and from a target illuminated byscanning signal 201. The round trip time is given as Δt=2R/v, where R isthe target range and v is the velocity of the optical beam, which is thespeed of light c. The target range, R, can therefore be calculated asR=c(Δt/2). When the return signal 202 is optically mixed with thescanning signal, a range-dependent difference frequency (“beatfrequency”) ΔfR(t) is generated. The beat frequency ΔfR(t) is linearlyrelated to the time delay Δt by the slope of the sawtooth k. That is,ΔfR(t)=kΔt. Since the target range R is proportional to Δt, the targetrange R can be calculated as R=(c/2)(ΔfR(t)/k). That is, the range R islinearly related to the beat frequency ΔfR(t). The beat frequency ΔfR(t)can be generated, for example, as an analog signal in optical receivers104 of system 100. The beat frequency can then be digitized by ananalog-to-digital converter (ADC), for example, in a signal conditioningunit such as signal conditioning unit 107 in LIDAR system 100. Thedigitized beat frequency signal can then be digitally processed, forexample, in a signal processing unit, such as signal processing unit 112in system 100. It should be noted that the target return signal 202will, in general, also includes a frequency offset (Doppler shift) ifthe target has a velocity relative to the LIDAR system 100. The Dopplershift can be determined separately, and used to correct (e.g., adjust,modify) the frequency of the return signal, so the Doppler shift is notshown in FIG. 2 for simplicity and ease of explanation. For example,LIDAR system 100 may correct the frequency of the return signal byremoving (e.g., subtracting, filtering) the Doppler shift from thefrequency of the returned signal to generate a corrected return signal.The LIDAR system 100 may then use the corrected return signal tocalculate a distance and/or range between the LIDAR system 100 and theobject. In some embodiments, the Doppler frequency shift of targetreturn signal 202 that is associated with an object may be indicative ofa velocity and/or movement direction of the object relative to the LIDARsystem 100.

It should also be noted that the sampling frequency of the ADC willdetermine the highest beat frequency that can be processed by the systemwithout aliasing. In general, the highest frequency that can beprocessed is one-half of the sampling frequency (i.e., the “Nyquistlimit”). In one example, and without limitation, if the samplingfrequency of the ADC is 1 gigahertz, then the highest beat frequencythat can be processed without aliasing (ΔfRmax) is 500 megahertz. Thislimit in turn determines the maximum range of the system asRmax=(c/2)(ΔfRmax/k) which can be adjusted by changing the chirp slopek. In one example, while the data samples from the ADC may becontinuous, the subsequent digital processing described below may bepartitioned into “time segments” that can be associated with someperiodicity in the LIDAR system 100. In one example, and withoutlimitation, a time segment might correspond to a predetermined number ofchirp periods T, or a number of full rotations in azimuth by the opticalscanner.

FIGS. 3A-3B are block diagrams depicting examples of rotating an opticalsource with two optical beams to change a vertical beam-to-beam spacingangle in one or more scan frames, according to some embodiments. FIG. 3Adepicts an example of a beam pattern 305 with two optical beams beingadjusted by rotating an optical source. Diagram 300 depicts a viewlooking into lens 310 of optical source 340, which shows the two opticalbeams 315 forming beam pattern 305 where the two optical beams 315 areseparated by y1 along axis 325. Axis 325, in one embodiment, is an axisin a vertical direction relative to the positioning of LIDAR system 100.

Diagram 330 depicts a side view of optical source 340 that transmits outbeam pattern 305 through lens 310. As discussed herein, the anglebetween optical beams 315 remains fixed as optical source 340 rotates.However, by rotating optical source 340, the vertical angle changes,which is denoted as yn°. Diagram 330 shows that beam pattern 305produces a vertical angle of y1° along axis 325.

Referring to FIG. 3B, optical source 340 may be rotated to form anadjusted beam pattern 355 such that optical beams 315 are separated byy2 along axis 325. Diagram 370 depicts a side view of optical source 340that transmits out beam pattern 355 through lens 310. As can be seen,the vertical angle along axis 325 changes from y1° in diagram 330 to y2°in diagram 370 to produce a narrower angle where y2° is less than y1°.

As discussed herein, a beam pattern rotation may be introduced to thebeam pattern at optical source 340 and/or at other components withinLIDAR system 100, such as at one or more scanners (e.g., 1D scanners,see, e.g., FIGS. 5A-5D and corresponding text for further details). Inone embodiment, optical source 340 may provide additional optical beamsthat, in turn, create a beam pattern that forms an adjusted beam patternutilizing the approach discussed herein (see, e.g., FIG. 4A-4B andcorresponding text for further details).

In some embodiments, optical source 340 may generate optical beams ofany wavelength (e.g., 905 nanometer (nm), 1550 nm) to cause the beampattern to include optical beams of the same wavelength or differentwavelengths. For example, optical source 340 may generate optical beamsthat include a subset of optical beams that have a wavelength of 905 nmto detect objects of a particular type (e.g., water, rain and fog, andsnow), and a different subset of optical beams that have a wavelength of1550 nm to detect objects of a different type (e.g., vehicles, streetsigns, pedestrian).

FIGS. 4A-4B are block diagrams depicting examples of rotating an opticalsource with four optical beams to change vertical beam-to-beam spacingangles, according to some embodiments. FIG. 4A depicts an example of abeam pattern 405 with four optical beams being adjusted by rotating anoptical source. Diagram 400 depicts a view looking into lens 410 ofoptical source 440, which shows four optical beams 415 forming beampattern 405 where the four optical beams 415 are separated by (y+a),(y−a), and (y+a) along axis 425. Axis 425, in one embodiment, is an axisin a vertical direction relative to the positioning of LIDAR system 100.

Diagram 430 depicts a side view of optical source 440 that transmits outbeam pattern 405 through lens 410. Diagram 430 shows that beam pattern405 produces vertical angles along axis 425 of (y+a°), (y−a°), and(y+a°).

Referring to FIG. 4B, using techniques similar to the approachesdescribed above in FIGS. 3A-3B above, optical source 440 may be rotatedto form an adjusted beam pattern 455 such that optical beams 415 areseparated by an equivalent vertical angle y° along axis 425. Diagram 470depicts a side view of optical source 440 that transmits out beampattern 455 through lens 410. As can be seen, the vertical angles alongaxis 425 between the beams is equivalent at y°.

As discussed herein, a beam pattern rotation may be introduced to thebeam pattern at optical source 440 and/or at other components withinLIDAR system 100, such as at one or more scanners (e.g., 1D scanners,see, e.g., FIGS. 5A-5D and corresponding text for further details). Insome embodiments, optical source 440 may generate optical beams of anywavelength (e.g., 905 nanometer (nm), 1550 nm) to cause the beam patternto include optical beams of the same wavelength or differentwavelengths. For example, optical source 440 may generate optical beamsthat include a subset of optical beams that have a wavelength of 905 nmto detect objects of a particular type (e.g., water, rain and fog, andsnow), and a different subset of optical beams that have a wavelength of1550 nm to detect objects of a different type (e.g., vehicles, streetsigns, pedestrian).

FIGS. 5A-5D depict various transformations of beam patterns performed byembodiments of the present disclosure. FIG. 5A shows an initialconfiguration that does not transform the beam pattern to the adjustedbeam pattern. Optical source 510 transmits the beam pattern to scanner520. Scanner 520 may be, for example, a 1D scanner that scans in thevertical direction relative to optical source 510. In the initialconfiguration, scanner 520 may transmit the beam pattern unaltered toscanner 530. Scanner 530 may be, for example, an azimuth scannerrelative to scanner 520 that transmits the beam pattern unaltered to theexternal environment.

FIG. 5B is a diagram depicting the beam pattern being transformed to theadjusted beam pattern at optical source 510, similar to that shown inFIGS. 3A, 3B, 4A, and 4B. Optical source 510 transmits the adjusted beampattern to scanner 520. Scanner 520 transmits the adjusted beam patternunaltered to scanner 530, which in turn transmits the adjusted beampattern to the external environment.

FIG. 5C is a diagram depicting scanner 520 transforming the beam patternto the adjusted beam pattern. Optical source 510 transmits the beampattern to scanner 520. Scanner 520 is configured to introduce arotational element into the beam pattern. The rotation element, in oneembodiment, is achieved by rotating scanner 520 about a different axisthat is not parallel (e.g., perpendicular) to optical source 510's beampattern output. As such, scanner 520 transforms the beam pattern intothe adjusted beam pattern, which scanner 520 transmits to scanner 530.Scanner 530 then transmits the adjusted beam pattern to the externalenvironment.

FIG. 5D is a diagram depicting scanner 530 transforming the beam patternto the adjusted beam pattern. Optical source 510 transmits the beampattern to scanner 520. Scanner 520 is not configured to introduce arotation element into the beam pattern and, in turn, transmits the beampattern to scanner 530. Scanner 530 is configured to introduce arotation element into the beam pattern by rotating scanner 530 about adifferent axis that is not parallel to optical source 510's beam patternoutput. In turn, scanner 530 transforms the beam pattern into theadjusted beam pattern and transmits the adjusted beam pattern to theexternal environment.

In one embodiment, scanner 520 may be configured to introduce a portionof the rotation element into the beam pattern and scanner 530 isconfigured to introduce the remaining portion of the rotation element toeventually produce the adjusted beam pattern from scanner 530.

FIG. 6 is a block diagram depicting an example of using a beammeasurement system to set a particular beam pattern in a LIDAR system,according to some embodiments. In some embodiments, beam measurementsystem 650 couples to LIDAR system 100, such as during factory test, toset a particular beam pattern and read an output beam pattern from LIDARsystem 100. Beam measurement system 650 may include hardware, software,or a combination of hardware and software.

Beam measurement system 650, in some embodiments, includes a camera thatreads beam spacings from beam pattern 620 and provides feedback 660 toinformation to signal processing unit 112. Signal processing unit 112,when executing beam pattern adjustment module 113, then directscontroller 116 to instruct adjustment components 117, 118, and/or 119 tomove optical circuits 101, free space optics 115, and/or optical scanner102 accordingly to form a desired beam pattern. In some embodiments,adjustment components 117, 118, and/or 119 include motorized stages,such as actuators, that adjust (e.g., rotate) scanners and/or opticalsources. In some embodiments, adjustment components 117, 118, and 119include components for adjusting at discrete increments, such as gears,magnets, and etc.

In some embodiments, signal processing unit 112, when executing beampattern adjustment module 113, communicates directly with adjustmentcomponents 117, 118, and 119 to move optical circuits 101, free spaceoptics 115, and/or optical scanner 102. In some embodiments, beammeasurement system 650 determines the vertical angle between the opticalbeams along an axis and provides the vertical angle to signal processingunit 112. Then, signal processing unit 112 determines the amount atwhich to adjust optical circuits 101, free space optics 115, and/oroptical scanner 102 via adjustment components 117, 118, and/or 119.

FIG. 7 is a block diagram depicting an example of a LIDAR system thatdynamically adjusts beam patterns in real-time based on point cloudanalysis. In field conditions, vehicle shock, vibration, and temperaturefluctuations may cause the beam angular spacings to change. FIG. 7 showsan embodiment of LIDAR control systems 110 analyzing a point cloud 770and adjusting one or more components in optical assembly 705 accordinglyto form a different beam pattern, such as a different beam pattern thatresults in non-uniform beam angular spacing in point cloud 770.

Optical assembly 705, in one embodiment, includes optical source 710,scanner 715, scanner 720, and beam pattern adjustment assembly 725.Optical source 710 is similar to optical source 340, 440, and 510discussed herein, and produces multiple optical beams that feed intoscanner 715. Scanner 715 is similar to scanner 520 from FIGS. 5A-5D, andscanner 720 is similar to scanner 530 from FIGS. 5A-5D. Beam patternadjustment assembly 725 include components that adjust optical source710, scanner 715, and/or scanner 720 to form a particular beam patternas discussed herein, such as actuators, gears, magnets, and etcetera.

Optical assembly 705 sends transmit optical beams 730 towardsenvironment 740. Transmit optical beams 730, in one embodiment, form abeam pattern, such as the adjusted beam pattern discussed herein.Transmit optical beams 730 reflect off of environment 740 to producereturn optical beams 750, which are captured by optical assembly 705(e.g., optical scanner 102 in FIG. 1 ). Signal data 760 is generatedfrom return optical beams and passes to LIDAR control systems 110, whichcreates point cloud 770 from signal data 760 (see FIGS. 1, 2 , andcorresponding text for further details).

LIDAR control systems 110 (e.g., beam pattern adjustment module 113)analyzes point cloud 770 to determine whether adjustments are requiredto the beam pattern. In one embodiment, LIDAR control systems 110determines that point cloud 770 includes unwanted gaps, such as due tothe beam pattern changing from vibration and/or environmentalconditions. In this embodiment, LIDAR control systems 110 determineswhat components from beam pattern adjustment assembly 725 to adjust andsends component adjustments 780 to optical assembly 705 accordingly. Forexample, LIDAR control systems 110 may determine that optical source 710requires a 1.2° counterclockwise rotation and sends instructions to anactuator coupled to optical source 710 to rotate optical source 710.

In one embodiment, LIDAR control systems 110 determines that point cloud770 includes an object and wishes to have increased resolutioninformation about the object. In this embodiment, LIDAR control systems110 determines what components in beam pattern adjustment assembly 725to adjust to “tighten” certain beam angular spacings and sends componentadjustments 780 to optical assembly 705 accordingly. For example, LIDARcontrol systems 110 may determine that a combination of rotating scanner715 and rotating scanner 720 will produce a beam pattern with tightenedbeam angular spacings. In this example, LIDAR control systems 110 maysend instructions to actuators coupled to scanner 715 and scanner 720,respectively, to rotate their corresponding scanners.

FIG. 8 is a flow diagram depicting an example method for transforming abeam pattern into an adjusted beam pattern, according to someembodiments. Additional, fewer, or different operations may be performedin the method depending on the particular arrangement. In someembodiments, some or all operations of method 800 may be performed byone or more processors executing on one or more computing devices,systems, or servers (e.g., remote/networked servers or local servers).In some embodiments, method 800 may be performed by a signal processingunit, such as signal processing unit 112 in FIG. 1 . Each operation maybe re-ordered, added, removed, or repeated. In some embodiments, method800 may be performed by processing logic including hardware (e.g.,circuitry, dedicated logic, programmable logic, a processor, aprocessing device, a central processing unit (CPU), a system-on-chip(SoC), etc.), software (e.g., instructions running/executing on aprocessing device), firmware (e.g., microcode), or a combinationthereof.

In some embodiments, the method 800 may include operation 802, where theprocessing logic receives a beam pattern from an optical source. In someembodiments, the beam pattern includes optical beams transmitted towardsa target to cause different spaces to form between each optical beam ofthe optical beams.

In some embodiments, the method 800 may include operation 804, where theprocessing logic measures a vertical angle between the optical beamsalong an axis relative to the FMCW LIDAR system. In some embodiments,the method 800 may include operation 806, where the processing logiccalculates an adjusted beam pattern based on the vertical angle and apivot point within the FMCW LIDAR system that causes the optical beamsto be transmitted towards the target with substantially uniform spacingbetween each optical beam of the optical beams.

In some embodiments, the method 800 may include operation 808, where theprocessing logic adjusts, at the pivot point, one or more componentsfrom a position that forms the beam pattern to an adjusted position thatforms the adjusted beam pattern in the FMCW LIDAR system to adjust thedifferent spaces to the substantially uniform spacing for transmissiontowards the target. In some embodiments, the method 800 may includeoperation 808, where the processing logic receives one or more returnoptical beams from the target, based on the adjusted beam pattern, toproduce points to form the point cloud.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent disclosure. It will be apparent to one skilled in the art,however, that some embodiments of the present disclosure may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present disclosure. Thus, the specific details set forth are merelyexemplary. While this specification contains many specificimplementation details, these should not be construed as limitations onthe scope of any inventions or of what may be claimed, but rather asdescriptions of features specific to particular embodiments ofparticular inventions. Certain features that are described in thisspecification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or variation of a sub-combination.Moreover, the separation of various system components in the embodimentsdescribed above should not be understood as requiring such separation inall embodiments, and it should be understood that the described programcomponents and systems can generally be integrated together in a singlesoftware product or packaged into multiple software products. Particularembodiments may vary from these exemplary details and still becontemplated to be within the scope of the present disclosure.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiments included inat least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.”

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operations may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittent oralternating manner.

The above description of illustrated implementations of the invention,including what is described in the Abstract, is not intended to beexhaustive or to limit the invention to the precise forms disclosed.While specific implementations of, and examples for, the invention aredescribed herein for illustrative purposes, various equivalentmodifications are possible within the scope of the invention, as thoseskilled in the relevant art will recognize. The words “example” or“exemplary” are used herein to mean serving as an example, instance, orillustration. Any aspect or design described herein as “example” or“exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs. Rather, use of the words“example” or “exemplary” is intended to present concepts in a concretefashion. As used in this application, the term “or” is intended to meanan inclusive “or” rather than an exclusive “or”. That is, unlessspecified otherwise, or clear from context, “X includes A or B” isintended to mean any of the natural inclusive permutations. That is, ifX includes A; X includes B; or X includes both A and B, then “X includesA or B” is satisfied under any of the foregoing instances. In addition,the articles “a” and “an” as used in this application and the appendedclaims should generally be construed to mean “one or more” unlessspecified otherwise or clear from context to be directed to a singularform. Moreover, use of the term “an embodiment” or “one embodiment” or“an implementation” or “one implementation” throughout is not intendedto mean the same embodiment or implementation unless described as such.Furthermore, the terms “first,” “second,” “third,” “fourth,” etc. asused herein are meant as labels to distinguish among different elementsand may not necessarily have an ordinal meaning according to theirnumerical designation.

What is claimed is:
 1. A method of adjusting a beam pattern to form apoint cloud in a frequency-modulated continuous wave (FMCW) lightdetection and ranging (LIDAR) system, the method comprising: receiving afirst beam pattern from an optical source, the first beam patterncomprising a plurality of optical beams transmitted towards a target tocause a plurality of different spaces to form between each optical beamof the plurality of optical beams; measuring a vertical angle between atleast two of the plurality of optical beams along a first axis relativeto the FMCW LIDAR system; calculating, using a processor, a second beampattern based on the vertical angle and a pivot point within the FMCWLIDAR system that causes the plurality of optical beams to betransmitted towards the target with substantially uniform spacingbetween each optical beam of the plurality of optical beams; adjusting,at the pivot point, one or more components from a first position thatforms the first beam pattern to a second position that forms the secondbeam pattern in the FMCW LIDAR system to adjust the plurality ofdifferent spaces to the substantially uniform spacing for transmissiontowards the target; and receiving one or more return optical beams fromthe target, based on the second beam pattern, to produce a plurality ofpoints to form the point cloud.
 2. The method of claim 1 wherein the atleast two optical beams form a first vertical angle corresponding to thefirst beam pattern and form a second vertical angle corresponding to thesecond beam pattern, wherein the first vertical angle and the secondvertical angle are both vertical components of angular separation in ascan frame between the at least two optical beams.
 3. The method ofclaim 1, wherein at least a portion of the adjusting of the one or morecomponents rotates the optical source about a second axis relative tothe first axis.
 4. The method of claim 1, further comprising: receivingthe first beam pattern generated by the optical source at a scanner; andwherein the adjusting further comprises rotating the scanner about asecond axis not parallel to the first axis.
 5. The method of claim 4,wherein the scanner is a first scanner, the method further comprising:receiving the first beam pattern from the first scanner at a secondscanner; and wherein the adjusting further comprises rotating the secondscanner until the second beam pattern is formed.
 6. The method of claim1, further comprising: analyzing the point cloud; and dynamicallyre-adjusting, responsive to analyzing the point cloud, the one or morecomponents to re-create the second beam pattern.
 7. The method of claim1, further comprising: detecting an object in the point cloud;determining a third beam pattern based on the object; and adjusting, atthe pivot point, the one or more components to a third position thatforms the third beam pattern in the FMCW LIDAR system.
 8. Afrequency-modulated continuous wave (FMCW) light detection and ranging(LIDAR) system comprising: an optical source to generate a first beampattern comprising a plurality of optical beams transmitted towards atarget to cause a plurality of different spaces to form between eachoptical beam of the plurality of optical beams; a memory to store a setof instructions; and a processor coupled to the memory that, whenexecuting the set of instructions, is configured to: measure a verticalangle between at least two of the plurality of optical beams along afirst axis relative to the FMCW LIDAR system; calculate a second beampattern based on the vertical angle and a pivot point within the FMCWLIDAR system that causes the plurality of optical beams to betransmitted towards the target with substantially uniform spacingbetween each optical beam of the plurality of optical beams; adjust, atthe pivot point, one or more components from a first position that formsthe first beam pattern to a second position that forms the second beampattern in the FMCW LIDAR system to adjust the plurality of differentspaces to the substantially uniform spacing for transmission towards thetarget; and receive one or more return optical beams from the target,based on the second beam pattern, to produce a plurality of points toform a point cloud.
 9. The FMCW LIDAR system of claim 8, wherein the atleast two optical beams form a first vertical angle corresponding to thefirst beam pattern and form a second vertical angle corresponding to thesecond beam pattern, wherein the first vertical angle and the secondvertical angle are both vertical components of angular separation in ascan frame.
 10. The FMCW LIDAR system of claim 8, wherein at least aportion of the adjustment of the one or more components rotates theoptical source about a second axis relative to the first axis.
 11. TheFMCW LIDAR system of claim 8, further comprising: a scanner thatreceives the first beam pattern; and wherein the adjusting furthercomprises rotating the scanner about a second axis not parallel to thefirst axis.
 12. The FMCW LIDAR system of claim 11, wherein the scanneris a first scanner, the system further comprising: a second scanner; andwherein the processor is further configured to rotate both the firstscanner and the second scanner until the second beam pattern is formed.13. The FMCW LIDAR system of claim 8, wherein the processor isconfigured to: analyze the point cloud; and re-adjust, responsive toanalyzing the point cloud, the one or more components to re-create thesecond beam pattern.
 14. The FMCW LIDAR system of claim 8, wherein theprocessor is configured to: detect an object in the point cloud;determine a third beam pattern based on the object; and adjust, at thepivot point, the one or more components to a third position that formsthe third beam pattern in the FMCW LIDAR system.
 15. Afrequency-modulated continuous wave (FMCW) light detection and ranging(LIDAR) system, the system comprising: an optical assembly comprising:an optical source and one or more scanners, wherein the optical assemblygenerates a first beam pattern comprising a plurality of optical beamstransmitted towards a target to cause a plurality of different spaces toform between each optical beam of the plurality of optical beams; and abeam pattern adjustment assembly, wherein the beam pattern adjustmentassembly further to adjust, at a pivot point, one or more componentsfrom a first position that forms the first beam pattern to a secondposition that forms a second beam pattern; and a LIDAR control systemcoupled to the optical assembly, comprising one or more processors,wherein the LIDAR control system to: measure a vertical angle between atleast two of the plurality of optical beams along a first axis relativeto the FMCW LIDAR system; calculate the second beam pattern based on thevertical angle and the pivot point within the FMCW LIDAR system thatcauses the plurality of optical beams to be transmitted towards thetarget with substantially uniform spacing between each optical beam ofthe plurality of optical beams; instruct the beam pattern adjustmentassembly to perform the adjusting; and receive one or more returnoptical beams from the target, based on the second beam pattern, toproduce a plurality of points to form a point cloud.
 16. The FMCW LIDARsystem of claim 15, wherein the at least two optical beams form a firstvertical angle corresponding to the first beam pattern and form a secondvertical angle corresponding to the second beam pattern, wherein thefirst vertical angle and the second vertical angle are both verticalcomponents of angular separation in a scan frame.
 17. The FMCW LIDARsystem of claim 15, wherein at least a portion of the adjustment of theone or more components rotates the optical source about a second axisrelative to the first axis.
 18. The FMCW LIDAR system of claim 15,wherein at least a portion of the adjustment rotates at least onescanner from the one or more scanners about a second axis not parallelto the first axis.
 19. The FMCW LIDAR system of claim 15, wherein theLIDAR control system further to: analyze the point cloud; and re-adjust,responsive to analyzing the point cloud, the one or more components tore-create the second beam pattern.
 20. The FMCW LIDAR system of claim15, wherein the LIDAR control system further to: detect an object in thepoint cloud; determine a third beam pattern based on the object; andadjust, at the pivot point, the one or more components to a thirdposition that forms the third beam pattern in the FMCW LIDAR system.